System for remotely controlling regulators



Aug. 26, 1941. H SCHRODER 2,253,654

SYSTEM FOR REMOTELY.CONTROLLING REGULATORS- Filed Oct. 19, 1937 iNVENTORH. SCHRODER Patented Aug. 26, 1941 SYSTEM FOR BEMOTELY CONTROLLINGnacum'roas Heinrich Schriider.

Berlin, Germany, assignor to Telefnnken Gesellschaft fiir DrahtloseTelegraphic in. b. 11., Berlin, Germany, a corporation of GermanyApplication 1 Claim.

For the electrical remote control of regulators. particularly of tuningmeans in transmitters and receivers, a number of proposals already hasbeen made. the apparatus to be controlled from a distance a shiftingmotor acting on the shaft of the regulator. which is switched on byactuating switch contacts placed at the control device and is au-October 19, 1937, Serial No. 169,794 Germany September 23, 1936 Thus, e.,g., one has provided on I tomatically disconnected as soon as thedesired I adjustment is reached It has been found, however, that thedevices of the prior art are quite complicated and in addition requireconsiderable space for proper' mounting and operation thereof. This hasbeen found to be a great disadvantage in some types of installationswhere it is essential to mount the controlling apparatus in a smallspace.

It is an object of the present invention to provide a remote controltuning arrangement which overcomes the disadvantages mentioned above.Other objects of the invention will be apparent from the followingdescription when considered in connection with the accompanying drawing.

In the drawing, Figure 1 illustrates in schematic form a preferredembodiment of the invention showing a motor controlled shaft; Figure 2is a detailed showing of the switch operating arm'of the arrangementshown in Figure 1; and Figure 3 isa diagrammatic illustration showingthe construction of one of the station switches.

In accordance with this invention an arm is coupled to the regulatorwhich opens in passingby one or more switches arranged according topredetermined desired settings. Each of these switches is joined inseries to the associated switch contact placed at the control device andthe shifting motor as well as the operating voltage source.

The invention renders possible an accurate remote control by simplemeans of little energy consumption and very small dimensions.

In Figure l of the drawing, W represents the shaft of the regulator, e.g. of a tuning means (condenser), or a shaft coupled to it by a gear.This shaft is driven by the shifting motor M through the intermediategearing V. Th shaft W carries an arm A consisting wholly or at least atits end remote from the shaft of insulating material. Concentrically to;the axis a rigid metal ring R is mounted supporting five switches S1 toS5 at positions corresponding to the predetermined settings of theregulator. switch consists of two elastic straps of sheet metal with onecontact member each, C1 and C2,

' assure that the Each (Figure 3) which normally touch one another. Oneof .the springs or elastic straps preferably B2 is conductivelyconnected to the ring R while the other is insulated from it byinsulator means X and is connected to the associated of the five switchcontacts K1 to K5, namely,K4 by a transmission line. The return pathruns through the motor and the operating voltage source 13 back to thering R. In Figure 1 the apparatus below the dotted line comprises thecontrol device which includes the five switch contact elements K1 to K5,and which may be located at a point remote from the receiver. Ifdesired, the voltage source B mayv also be located at the control point.j

The operation is as follows: As soon as one of the switch contacts, e.g. K2, is depressed, a circuit for the shifting shaft W is turned untithe arm A has reached the switch'Sz and passes through between theelastic straps B1, B2 of the switch whereby the contact members 01, C2associated therewith are separated from each other by bending-off andthe motor circuit is interrupted. In this way the motor and theregulator are stopped thus tuning in the desired transmitting station.

In the present arrangement it will be noted that the torque required ofthe motor is comparatively small since the shaft runs substantiallyunloaded (apart from the friction of the regulator itself) except at themoments when the arm A passes through a switch; while in contrastthereto in systems heretofore used, all contact springs sweep thecommutator at all times. Accordingly, with the present arrangement it ispossible to employ a motor having very small dimensions and very lowcurrent consumption.

While the invention has been described in connection with a motor whichoperates in one direction only, it should be understood that the variousfeatures of the invention may be applied to systems wherein the motor isreversible, such as shown in the Gunther et a1. United States Patent No.1,911,021 issued May 23, 1933.

In the event that the invention is applied to an arrangement such asshown in the above mentioned patent, great care must be taken to pointat which the motor is desired" to be stopped is independent of thedirection of approach of that point. For this purpose, it is desirableto arrange the arm A as shown in Figure 2 wherein the part of the armwhich is connected to the shaft carries an insulating lever arm Tpivoted on the ioumal D which is limited motor is completed. The

as regards to its movements by a pair of stop pins N, N. The lever armis thus permitted to shift in the direction of rotation of the arm by adistance approximately equal to its width. The tip of the lever arm Tcooperates with the switches 81 to S: in such a way that when the leverarm- '1 comes in contact with one of the switches, the lever arm firstmoves back to the stop pin and then acts to spread the elastic strapsapart from each other so as to open the contact elements C1, C: (seeFigure 3). In this way it is assured that the adjustment is alwaysexactly the same irrespective oi whether the arm A approaches a switchfrom the right or the left What is claimed is:

'In a remote control system for radio receiving apparatus and the like,including a control shaft, a selector control mechanism comprising acurved member concentrically mounted with respect to the shaft, aplurality of operable switches positioned on said member according topredetermined settings, a radial arm device connected to said shaft androtatable therewith, said arm including a pivoted member mounted nearthe end thereof away from the shaft, said pivoted member having apredetermined limited movement about its pivot point, said switchesbeing arranged so as to be in the path oi said pivoted member and sothat any one 01' said switches is contacted and opened by said pivotedmember when the shaft is rotated to a position which brings the pivotedmember into contact with that particular switch, the amount of movementof said pivoted. member being adjusted so that th connection between anyparticular switch and the pivoted member is made and the switch openedat substantially the same position of said shaft whether the armapproaches the contact from one side thereof or the other.

HEINRICH SCHRCDER.

